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I have an LS one Corvette engine just swapped into my 1971 Camaro with a 4L 60 E transmission being controlled by a TCI TCU controller. I’m having trouble getting it to shift without high revs. To get it to shift into third or fourth gear, I have to Rip up to nearly 4000 RPM like I’m drag racing down the street. I have tried all the adjustments on the TCU and don’t know what to do.
Last edited by mrvedit; Aug 22, 2023 at 11:22 AM.
Reason: Added "TCI Controller" to title
I have an LS one Corvette engine just swapped into my 1971 Camaro with a 4L 60 E transmission being controlled by a TCI TCU controller. I’m having trouble getting it to shift without high revs. To get it to shift into third or fourth gear, I have to Rip up to nearly 4000 RPM like I’m drag racing down the street. I have tried all the adjustments on the TCU and don’t know what to do.
Is this a GU transmission or a rebuilt one?
First your going to have to look at shift commands at a lower speed. What are they commanding?
If it is not commanding the shift until (a few seconds before) it actually happens. You have an issue with the trans tune in your TCI controller or it can be as simple as a vacuum leak to the map sensor or low manifold vacuum..
If it is commanding the 1-2 shift at 15 MPH but drags out to 25 that is something internal to the shift valve. It could be a bad AFL(Actuator Feed Limit) bore and have low AFL pressure tot the shift valves.
Basically the controller should be looking at 3 things for controlling the shifts.
1st the TPS for where your foot is asking for the command to happen. Low throttle or high throttle.
2nd it should look at the engine load (MAP) and correlate between the two. Is it really have a high load or is it really a light load.
3rd it will calculate a MPH that a shift is requested.
All of that is in a predetermined algorithm in the controller. I have no real world experience with a TCI controller. You will need to know or find out how it is supposed to calculate shift MPH. I do know that the MSD Atomic only uses a TPS signal to calculate a shift MPH.
Maybe Someone else has a personal experience with a TCI Controller. What part # is it anyway?
Do you have the TPS connected and is there a way to test it?
I see that TCI also sells an RPM module for at least some of their controllers. Do you have that?
I spoke with TCI today and we both came to the conclusion that something is amiss involving the TPS with the DBW pedal. I am going to try to connect to a different wire down there...
Different model DBW pedals put out different voltage ranges . You may have to verify that the TCI supports your particular DBW part number. DBW pedals basically have either 2 or 3 potentiometers. Each is connected to 5V and ground and the center connection produces a voltage corresponding to the throttle position. The ECU checks that the 2/3 potentiometers are putting out the same (within reason) signal to ensure that a single failure won't give you WOT. If they are different you get limp mode.
Assuming you have the +5V and Ground connected properly, you an easily check that the voltage changes with position.
Here is the pin out for my DBW Corvette pedal... I am using one of the 5v reference wires for my TPS with an inline 80k resistor, I can't remember which wire, I will try the other one...
MaroonMonster is absolutely correct.
Put a volt meter on the selected APP Sensor wire and confirm that it changes from e.g. 1.0 - 4.0 Volts. If it doesn't change/register, then either the 5V Reference or Low Reference is not connected.
The 5 volt reference will not work for any TPS signal
It's just a fixed 5v
You need a signal wire that will do a "sweep" with throttle input
Should be 0-1 volt when off throttle
And 4-5 volts at full throttle
Use a multi meter...the TCI likely has a "tps autoset" function...once you verify you have the right signal wire and voltage range, use the tps autoset
For the life of me I cannot get this to work. I found the signal wire but it only sweeps from 4.0 down to 2.1v. I used this to calibrate the TPS using the control unit. It says its calibrated and when engine is off it shows a 0 to 100 sweep when I press the throttle but when I crank the engine, it loses the calibration and just shows 0 on the handheld for TPS% and occasionally freezes at 34%. As a result my shift to 4th is very difficult and revs to 4000rpm.
I ordered a new TPS sensor for the pedal but I do not know what else to do...
No one else is there with your car and a multimeter.
You're the only one that can figure this out.
Clearly, it has been figured out by the hive mind already that there is clearly a TPS signal issue to the controller. It's your job as the builder to find out how/where/why that issue lies...then correct it.
I find it hard to believe that no one can figure this out...
I always suggest people add their City/State to their displayed info. Many members here are happy to help someone local.
Sorry you have received some "snippy" remarks, but....
Please keep in mind that you are connecting a GM component to a non-GM and rather obscure aftermarket TCM. Perhaps someone on a FAST forum knows that TCM real well. I suspect that either this GM part will never work, or there is a wiring error or perhaps incorrect assumption about what the wiring should be.
I always suggest people add their City/State to their displayed info. Many members here are happy to help someone local.
Sorry you have received some "snippy" remarks, but....
Please keep in mind that you are connecting a GM component to a non-GM and rather obscure aftermarket TCM. Perhaps someone on a FAST forum knows that TCM real well. I suspect that either this GM part will never work, or there is a wiring error or perhaps incorrect assumption about what the wiring should be.
Yes I would input more but really I do not know enough about that controller and could not find much either when I tried. One of the reasons I am partial to the USSHIFT controller even though some Do not care for it, Its just so incredibly simple as is its software. I like simple.
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Shifting issues with 4L60e and TCI Controller 
